Burner for solid fuels



A June 23, 1925. Q 1.542.852

A. BUSCH summa Fon soun FUELS Filed Patented June 23, 1925.

.UNITED STATIEISj AUGUSTO BUSCH, .0F BASEL, SWITZERLAND, ASSIGNOR T THEFIRM LEKTRIZITALS- Y I LONZA, OF'BASEL, SWITZERLAND. g

1,542,852 PATENT clerics.`

BURNER ron SOLID FUELS. f

fuappiigcation mea August 15, `1922. serial No. 5152,058.

To vall icl-zout it mijconccrn: I y

Be it known that LAUGUsTo BUSCH, a

subject of the King of Italy,A and resident of Y Basel, Switzerland, have invented new-and useful Improvements inBurners for Solid Fuels,of which the following is a full, clear, and exact specification.

'l The objectV of this invention is a burner for solid fuels, especially metaldehyde. In the construction of such a burner, regard must be' had to the special qualities of these new fuels, especially the cle-polymerization of the metaldehyde under the effect of heat. This fact makes of first importance the complete utilization of the vcalorificvalue ofthe fuel under. consideration for in earlier constructions of burner, a part'of the products of-de-polymerization was not burnt. p

Furthermore as is well known, if the air admission is. insufficient, all solid fuels burn with a more or less sooty flame., Compressed metaldehyde certainly showsthis defect very little. I'f'however, the boiler is placed close above vthe fuel and the -flamebeating upon the boiler takes a mushroom like shape, even metaldehvde forms a small quantity of soot.

It wouldbe possible to avoid this sooty -forf mation by simply perforating thev plate which s upports the fuel and so providing .for sufficient access of air. Such simple perforated plates have howevertwo faults; in the first place in the case of fuel which produces gases on burning, as for instance metaldehyde does, a part of the gases escape downwards through the holes and spread out, and a part of thecalorific value is lost. Further, there is a danger that pieces of fuel fall through and damage the table or the like on which the burner is standing.

Now it has been found that all these disadvantages can be avoided if there is provided beneath the perforated fuel support, a chamber with abundant access of air. 'Io make the access of air as considerable as possible, large openings are made in the bottom and preferably also in the sides of the chamber. In some cases, the side walls of said chamber may be wholly omitted, there being nothing more than such wires or stays as are necessary to connect the bottom firmly with the top or fuel plate of the chamber; the burner' then consists of two superposed perforated plates, the upper of which is the actual fuel support. In order that fuel may not falll out of the chamber, ,the holes in the two plates are relatively staggered-yk i It is of advantage to form 4the plates with grooves or in any other way to make their surface "uneven, so that thereis as little surface of contact as'possible between the fuel and its support; that is to say the air can reach the surface of the fuel from vall sides at as many points as possible. This strengthens substantially the flame.

, Such a burner vexhibit-s afnumber of peculiarities and advantages which are summmarized in" the following. It should be lnoted that the burner can, only be used for Asuch fuels as do not melt during burningand are in part converted into gas.

The gas which passes downwards through the holes in the top of the chamber which serves asa fuel support, comes first into the chamber; since in this chamber there is a draught of air directly upwards the gas is driven into the flame space and there` burns, it is therefore quantitively consumed.. lBut in partthe gas burns in the chamber itself and so heats the fuel supportand promotes ltheconversion of fuel into gas. f Pieces of fuel which fall through'the holes in the top of the chamber are caughtat the bottom of thechamber where they -go on burning until consumed.

In most burners soot formation is dependent upon the amount and height of the layer of fuel and upon the distance betweeny the Vfuel and the article to be heated. In the present burner there. is no formationof soot at all; so without fear of making the article to be heated sooty, as much of the fuel can be put beneath it as there is room for; but the burner also does not produce soot even if there is very little fuel.

As a rule the shape of a flame depends upon the shape of the fuel so that, for instance, rods of fuel give a long flame. In the present burner, the flame takes the form and size of the burner so that a round flame `throughout the chamber.

The fuel support and chamber herein described can. be mounted onv any desired stand, for instance upon a folding stand and may be connected` with it in various ways, for instance in such a manner that its height can be adjusted.

It lis obvious that this burner is not regulatable at will, but producesV a fla-me thesize of which depends upon the amount of the fuel and upon `the size of the plate and of the holes in it. But the 'llame can be made regulatable if the burner is placed vin a metal container or casing which is provided on its side or bottom with holes for the radmission of airwhich are regulatable in size; for instance such a variation may be obtained by means of a perforated revoluble disc lying on the floor of the casing or of 'slides or the like; for instance in a burner of the size shown in the drawing 30 grammes of fuel are consumed in ten minutes if the holes in the bottom are fully open. By partly closing the holes the fiame can be so diminished that the 30 grammes of fuel take about half an hour to burn. To increase the air draught a hood may be placed upon the case and will serve as a chimney. n

In theaccompanying drawing:

Figure l shows the improved burner in vertical section and FigureV 2 is a horizontal section thereof along the line 2 2 of Figure l.

T, is the upper perforated plate which forms the support for the fuel M, T2 is the lowerplate of the burner, and the space between T1 and T2 is the aforesaid regulating chamber.v In this chamber the small flames Z play, heating the plate T1 to promote the conversion Vof fuel into gas. F1 indicates the shape of the main iame, if the described double plate burner is employed alone. If a regulatable flame is wanted, the double plate burner supported by the' central p-ost S is surrounded by the Vcasing U, to the bottom of which the post is fastened. The bottom of the casing U is provided with air admission apertures L1. Upon it is arranged a disc with apertures L, which is revoluble by means of the handle H and more or less closes the holes L1. Any other suitable contrivance can be employed for this purpose. F2 indicateszthe form'of the main flame when such a surrounding casing is used and when its bottom aperturesare s fully opened.

`What I claim is 1. A burner for solid fuel of metaldehyde, comprising a casing, air admission means thereon, a support plate for the solid fuel within said casing, a lower plate arranged to define a secondary combustion chamber with said fuel support plate, yanannular air passage round said chamber for admission of air to the fuel on its support plate, large apertures in the latter for allowing fuel vapours to sink down .into said chamber, large air admission apertures in the lower plate for the combustion of said fuel vapours within said'chamber, to allow 4of formation of invert heating'ilames, substantially as and for the purpose described.

2. A burner for solid fuel' of metaldehyde, comprising a casing, air admission means thereon, a support plate for'the solid fuel within said casing; a lower plate arranged to define a secondary combustion chamber with said fuel support plate, an annular air pass-age around said chamber for admission of air to the fuel on itssupport plate, large apertures in the latter for allowing fuel vapours to sink down into said chamber, large air` admission apertures in the lower plate arranged in staggered position with respect to those of the fuel supportplate for the combustion of said' fuel vapours within said chamber,to allow o-f formation of invert heating flames, substantially as and for purpose described. Y

In witnesswhereof I have hereunto signed myname this 29th day of July 1922, in the presence of two subscribing witnesses.

AUGUSTO BUSCH. Witnesses: I

AMAN BEAUN, LUCIEN PICARD, 

